Earth:Emporia Formation
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| Emporia Formation Emporia Limestone Stratigraphic range: [1]Gzhelian (Virgilian stage)[2] | |
|---|---|
 Parallel jointing in the hard Elmont Limestone at Pillsbury Crossing | |
| Type | Formation |
| Unit of | Wabaunsee Group Oklahoma: Vamoosa Group |
| Sub-units |
|
| Underlies | Willard Shale |
| Overlies | Auburn Shale |
| Lithology | |
| Primary | Limestone, shale |
| Other | Sandstone |
| Location | |
| Region | Kansas |
| Country | United States |
| Type section | |
| Named for | Emporia, Kansas |
| Named by | R.C. Moore and M.R. Mudge[2] |
| Year defined | 1956 |
The Emporia Formation, also referred to as Emporia Limestone, is a Late-Carboniferous geologic formation in Kansas, extending into Nebraska, Iowa, Missouri, and Oklahoma.[2][1]
This formation's members are, top to bottom,
- Elmont Limestone, named for Elmont, Kansas (Beede, 1898)[3]
- Harveyville Shale, named for Harveyville, Kansas (Moore, 1936)[4]
- Reading Limestone, named for Reading, Kansas (Moore, 1936)[5]
While the Elmont Limestone member is generally less than 3 feet thick (1 meter), it can be as thick as 15 feet (5 meters)[3] and as thin as 12 inches. As thin as that, it is particularly resistant and forms multiple waterfalls within a few miles along Deep Creek in southern Riley County, including Pillsbury Crossing.[6][7] At Pillsbury Crossing, the Elmont Limestone is seen with parallel joints (pictured); and where not thickly covered with algae, the surface shows curious parallelogram patterns.
See also
- List of fossiliferous stratigraphic units in Kansas
- Paleontology in Kansas
References
- ↑ 1.0 1.1 P. H. Heckel (2013). "Pennsylvanian stratigraphy of Northern Midcontinent Shelf and biostratigraphic correlation of cyclothems". Stratigraphy 10 (1–2): 7, TEXT-FIGURE 4. https://www.researchgate.net/publication/269699418. Retrieved 2024-06-02.
- ↑ 2.0 2.1 2.2 "Geologic Unit: Emporia". National Geologic Database. United States Geological Survey. https://ngmdb.usgs.gov/Geolex/UnitRefs/EmporiaRefs_7635.html.
- ↑ 3.0 3.1 "Geologic Unit: Elmont". National Geologic Database. United States Geological Survey. https://ngmdb.usgs.gov/Geolex/UnitRefs/ElmontRefs_7622.html.
- ↑ "Geologic Unit: Harveyville". National Geologic Database. United States Geological Survey. https://ngmdb.usgs.gov/Geolex/UnitRefs/HarveyvilleRefs_8340.html.
- ↑ "Geologic Unit: Reading". National Geologic Database. United States Geological Survey. https://ngmdb.usgs.gov/Geolex/Units/Reading_10088.html.
- ↑ Jewett, John M. (1941). The Geology of Riley and Geary Counties, Kansas, Kansas Geological Survey Bulletin 39. University of Kansas Publications, State Geological Survey of Kansas. https://www.kgs.ku.edu/General/Geology/Riley/strat02.html. "... It breaks with wavy, irregular fracture and commonly occurs in beds about 7 inches but locally it is as little as 12 inches. ... Distribution--The Elmont limestone is exposed in Deep Creek valley south and east of Zeandale in Riley County, in secs 27,28,32, and 33,10 S., R. 9 E., and in secs. 5 and 6, T. 11S., R. 9 E. In several places in the last two sections enumerated, the limestone gives origin to small waterfalls in Deep Creek. Along the creek it is either faulted or slightly folded. It forms the natural ford at Pillsbury Crossing in sec. 5, T. 11 S., R. 9 E."
- ↑ "Pillsbury Crossing Wildlife Area". Kansas Geological Survey. https://geokansas.ku.edu/pillsbury-crossing-wildlife-area.
Note: The thickness given here is for the remnant ledge of the waterfall. As can be seen along the shores of the crossing, the upper beds of the Elmont Limestone described by Jewett have been washed away within the channel.
Note: The boulders below the waterfall also include Tarkio Limestone.
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